Postgresql function max_of

readme.md

max_of

returns the label for the max column of a row for each row

Say you have a table cat_dogs:

	no_cats	no_dogs
1	10	0
2	5	6
3	1	2

SELECT max_of(Array[no_cats,no_dogs], Array["cats","dogs"]) AS dominant_animal, * 
FROM cat_dogs

the function will return

	no_cats	no_dogs	dominant_animal
1	10	0	cats
2	5	6	dogs
3	1	2	dogs

example.sql

select max_of(Array[1,2,3],Array['one','two','three'])

max_of.sql

create or replace function max_of(vals numeric[], names text[]) returns text as $$
DECLARE
max_val numeric;
BEGIN
 max_val = (select  max(a) from unnest(vals) a);
 for i in 0..array_length(names,1) loop 
  if vals[i] = max_val then
    return names[i];
  end if;
 end loop;
END 
$$
LANGUAGE plpgsql